NGC 2264 is a young Galactic cluster and the dominant component of the Mon OB1 association lying approximately 760 pc distant within the local spiral arm .
The cluster is hierarchically structured , with subclusters of suspected members spread across several parsecs .
Associated with the cluster is an extensive molecular cloud complex spanning more than two degrees on the sky .
The combined mass of the remaining molecular cloud cores upon which the cluster is superposed is estimated to be at least \sim 3.7 \times 10 ^ { 4 } M _ { \odot } .
Star formation is ongoing within the region as evidenced by the presence of numerous embedded clusters of protostars , molecular outflows , and Herbig-Haro objects .
The stellar population of NGC 2264 is dominated by the O7 V multiple star , S Mon , and several dozen B-type zero-age main sequence stars .
X-ray imaging surveys , H \alpha emission surveys , and photometric variability studies have identified more than 600 intermediate and low-mass members distributed throughout the molecular cloud complex , but concentrated within two densely populated areas between S Mon and the Cone Nebula .
Estimates for the total stellar population of the cluster range as high as 1000 members and limited deep photometric surveys have identified \sim 230 substellar mass candidates .
The median age of NGC 2264 is estimated to be \sim 3 Myr by fitting various pre-main sequence isochrones to the low-mass stellar population , but an apparent age dispersion of at least \sim 5 Myr can be inferred from the broadened sequence of suspected members .
Infrared and millimeter observations of the cluster have identified two prominent sites of star formation activity centered near NGC 2264 IRS1 , a deeply embedded early-type ( B2–B5 ) star , and IRS2 , a star forming core and associated protostellar cluster .
NGC 2264 and its associated molecular clouds have been extensively examined at all wavelengths , from the centimeter regime to X-rays .
Given its relative proximity , well-defined stellar population , and low foreground extinction , the cluster will remain a prime candidate for star formation studies throughout the foreseeable future .